previous year question paper
1. The size of an electrode is designated by
a. diameter of core wire b. overall diameter c. length of electrode d. none of these
2. Buckling and bowing due to heat from welding is called :
a. distortion b. contraction c. over heat d. none of these
3. On acetylene gas systems, left threads are used :
a. on torches only b. on hoses only c. on cylinders only d. throughout
4. Which out of the following gases when combined with oxygen gives the highest LA temperature flame?
a. Hydrogen b. Natural gas c. Propane d. Acetylene
5. The purpose for which regulators are used on high pressure oxy-acetylene welding system is :
a. to increase the velocity of gas b. to reduce the cylinder pressure to working pressure
c. to control the temperature f flame d. to purity the gas before it reaches the
6. On high pressure oxygen connections, oil or grease should not be used for the following reason
a. spanner may slip b. explosion may be caused c. connections may become loose
d. connection may foul
. 7. The principle of mixing chamber of injector type blowpipe is based upon the :
a. Archemedes' principle b. Venturi principle c. Hooke's Law d. none of these
8. If a high pressure oxygen jet is directed on to a red hot M.S. plate, it causes :
a. melting of metal b. endothermic reaction c. chemical reaction d. none of these
9. Which is the fuel gas used for underwater cutting below 10 m?
a. Hydrogen b. Propane c. Acetylene d. none of these
10. What is indicated by the "drag” lines the kerf wall ?
a. speed of cutting b. nozzle size c. oxygen pressure d. height of nozzle
11. The reason for making nozzle from copper or copper alloys is :
a. it can be easily machined b. it is easy to work c. it dissipates heat quickly d. none of these
12. What type of flame is used for acetylene cutting of steel ?
a. neutral b. oxidizing c. carburisin g d. none of these D
13. For capillary attraction, the gap should be:
a. narrow b. wide c none of these
14. A brazing or bronze welding filler must melt at a temperature :
a. above that of parent metal b. below that of parent metal
c. same as that of parent metal d. none of these
15. A corrosive flux is not used on electrical assemblies because:
a. it may cause fire b. it may bum fingers c. it may cause explosion d. it may corrode the joint
16. The type of flame which is used for gas i welding of copper is :
a. neutral b. oxidizing c. carburizing d. none of these
17. 155. Tip size for welding of copper plates as compared to that for same thickness of steel is:
a. smaller b. larger c. same d. none of these
18. What is usually done if electrode sticks to the plate ?
a. to wait till it becomes red hot and melts b. to free it immediately by a quick and twisting motion
c. none of these
19. 160. In bend test, the metal on the outside
a. twisted b. stretched c. buckled d. none of these
20. Weld metal is not ductile, it if during bend test
a. gets icnce, b. gets thinner c. fractures d. none of these
21. Ohm's law says :
a. voltage :s proportional to resistance b. current is proportional to resistance
c. current is proportional to voltage
22. Which is stronger
a. soldered joint b. brazed joint c. none of these
23. What does percussion welding require in place of welding transformer ?
a. AC transformer b. DC generator c. the electrostatic capacitor d. none of these